Automatic sawmill method and apparatus

Abstract

A cant or plank is moved forwardly on a conveyor system, where its irregular leading lateral edge is measured by a plurality of fixed scanners. In response to measurement of the cant, conveyor movement is altered for orienting the cant relative to a predetermined saw line to be executed by a movable saw whereby the wane will be removed tangentially thereof. The cant is held or clamped in stationary position while the saw is moved on a carriage relative thereto, resulting in severing of the undesired irregular forward edge. The sawn edge is employed as a reference as the cant is then moved forwardly on a conveyor system, where the measurements obtained from the scanners may be further utilized in cutting the cant into desired widths.

We claim: 
     
       1. The method of processing cants sawn from logs and characterized by a longitudinal dimension acquired lengthways from a said log and a width dimension acquired crossways of said log and having at least one irregular lateral edge, said method comprising: detecting the irregular lateral edge of said cant to ascertain irregular indentations in said lateral edge,   automatically selecting indentations on said lateral edge for determining a straight saw line,   detecting if other indentations on said lateral edge fall within said saw line,   redetermining said saw line to extend in substantially tangential relation through at least one such other indentation until no other indentations fall within said line,   and sawing said cant along said saw line for substantially removing the irregularities of said lateral edge.   
     
     
       2. The method of processing cants sawn from logs and characterized by a longitudinal dimension acquired lengthways from a said log and a width dimension acquired crossways of a said log and having at least one irregular lateral edge, said method comprising: detecting said irregular lateral edge at a plurality of points,   automatically selecting a pair of said points for determining a straight saw line therebetween,   detecting if other points on the lateral edge of said cant fall within said line,   redetermining said saw line to include at least one such other point until no other points fall within said line,   and sawing said cant along said saw line to remove said irregularities from lateral edge.   
     
     
       3. The method according to claim 2 wherein said detected lateral edge points are wane points located on the wane of a said cant within predetermined tolerance of acceptable wood thickness. 
     
     
       4. The method of processing cants sawn from logs and characterized by a longitudinal dimension acquired lengthways from a said log and a width dimension acquired crossways of said log and having at least one irregular lateral edge, said method comprising: detecting the irregular forward edge of said cant at a plurality of points by directing radiation beams at spaced locations along the length of said cant, producing relative movement between said cant and said radiation beams, and detecting said radiation beams at a plurality of points as affected by the irregular lateral edge of said cant,   selecting a pair of said points on the lateral edge of said cant for determining a straight saw line therebetween,   detecting if other of said points on the lateral edge of said cant fall within said straight saw line,   redetermining said saw line to include at least one such other point until no other points fall within said saw line,   and providing relative movement between a cant and a saw along said saw line to remove irregularities on the said lateral edge of said cant.   
     
     
       5. The method according to claim 4 including angularly reorienting said cant for aligning the redetermined saw line with said saw.